Australian Antarctic Division: Leading Australia’s Antarctic Program

Ice sheets and sea level rise

Ice loss from the ice sheets of Antarctica and Greenland is contributing to sea level rise at an accelerating rate. Much of this loss is due to increased discharge of ice by the large glaciers draining the ice sheets, rather than by surface melt. However, the ice sheet response to climate change is poorly understood, leading to uncertainty in projections of sea level rise over the next century and beyond.

More reliable estimates of ice sheet contributions to present-day sea level rise are required, based on field and satellite observations. These estimates need to identify the regions where changes are most pronounced. The accuracy of satellite estimates of Antarctic mass balance change (ice gain and loss) is presently limited by inadequate knowledge of the rate of ‘glacial isostatic uplift’ (where the land rises as the weight of the ice sheet covering it diminishes). Research is needed to improve glacial isostatic adjustment models for Antarctica.

Our research aims to improve the estimates of ice loss from the Antarctic ice sheet for incorporation in sea level projections for 2050, 2100 and beyond. It will focus on:

What processes control ice loss from the Antarctic ice sheet and how will this influence future sea level rise?

What is the present state and rate of change of Antarctic ice mass?

To answer these questions scientists will:

use long-term satellite measurements and new remote sensing technologies to estimate the ‘mass budget’ (gain and loss of ice) of the ice sheet

use airborne geophysical surveys to acquire data that provide a better understanding of conditions beneath the ice sheet and ice shelves, such as the interactions between the ocean, ice shelves and glacier streams

collect evidence of past and present ice sheet positions

use all this information to improve computer models that can reproduce the variability and history of major ice sheets and provide more accurate projections of future change.